Photosis is a technology platform that incorporates high-speed optical scanning of biological samples, image analysis, and computer-controlled laser-irradiation of specific targets within the sample for the purpose of inducing a biological response. Specific cells to be treated within a mixed population are identified by parameters such as size, shape, fluorescence, or other distinguishing features. Once identified, individual cells are targeted with a laser to induce a desired response, such as cell death, optoporation (for gene transfer), or even inactivation of a specific mRNA transcript within the cell. The current beta1-prototyle system can process hundreds of millions of cells in an hour under sterile conditions, making it useful for several research and clinical applications. In fact, this prototype has several advantages over other methods of cell processing such as flow cytometry, and this conclusion is supported by preliminary data shown within. Photosis has many potential uses, and this proposal brings together a number of institutions and researchers to investigate and define the possible applications of this novel technology. In its current configuration, the instrument uses a single color for cell detection and a laser to induce necrosis in every targeted cell. These capabilities enable the first application, which is tumor cell purging from autologous NHL stem cell transplants, because such contaminating tumor cells are known to contribute to disease relapse. Additional applications will be developed, some of which will require modifications to the system design and building of new prototypes. The prototypes will be placed at four partnership sites where the basic and clinical applications research will be carried out, including: 1) in vivo study of purified stem cell subpopulations in the xenogeneic fetal sheep transplant model; 2) human clinical trials to assess NHL purging in autologous stem cell transplantation; 3) purification of genetically- modified stem cells and T-cells expressing a selectable transgene, as well as selective transduction of specific cells in a mixture via optoporation; and 4) accurate mRNA expression profiling from purified primary human prostate cancer cell populations. PROPOSED COMMERCIAL APPLICATION: The proposed work will result in several types of novel bioengineering instrumentation for advancing the state-of-the-art in cell processing. These instruments will be used in this program to advance basic and clinical research in stem cell biology, cancer, immunology, and genomics. Once developed, the resulting technology will be useful in other areas as well, some of which are described within.